Assessing the Tree Canopy in the City of Frederick

For clean air and water, energy savings, and overall health, the city of Frederick has a goal of 40 percent tree canopy coverage. Tree canopy, the layer of branches, stems and leaves that cover the ground when viewed from above, for the city stands at 20 percent, according to the latest Tree Canopy Report. That’s a bit more than the 14 percent we had in 2009, but still only half way to the goal. The increase is not attributed to planting more trees, but the availability of better imagery. This new assessment accounts for trees as small as eight feet tall, which hadn’t been mapped in the previous study.

Watersheds were evaluated for canopy coverage and at 28 percent. Rock Creek is the most forested, but still could use more trees. The Monocacy direct drainage in the southeastern area of the city stands at 9 percent canopy coverage because it is mostly agricultural fields. If those areas become developed, any floodplain land will be transferred to the city and much of it planted to protect the waterway.

The most recent tree canopy report differentiates canopy by land uses. Residential land is by far the largest land use in the City, but is only 24 percent forested. An additional 24 percent of already vegetated spaces, mostly lawns, in residential areas could be forested.

Frederick has been a Tree City USA for nearly 40 years and continues to plant wherever possible on city land, especially in parks. Every land use could improve canopy coverage, but residential areas have the most room for improvement. The real dilemma is convincing homeowners and homeowner associations that trees are better than open, mowed spaces.

Perceptions are everything and many homeowners feel that trees are trashy and drop too many leaves, fruits, or seeds that need to be raked. However, the real benefits of trees make them worth any perceived problems. A well-placed tree can reduce summer air conditioning costs by up to 35 percent, while a well-placed evergreen buffer can help save up to 30 percent on winter heating costs. Urban heat islands, areas with highly impervious surfaces, can have temperatures up to 22 degrees higher than the surrounding rural areas. Trees in urban spaces can help keep those areas cooler. Trees also can help take up excess nutrients in stormwater and capture particulate matter in the air, especially those with hairy leaves. Studies show that children with access to green spaces have fewer behavioral issues and perform better on tests.

There are plenty of tree species that do not drop excessive amounts of fruits or seeds and some are bred to not produce them at all. I’ve always said that if you have the space, plant an oak, but some yards just don’t have the space to accommodate one. Marylanders Plant Trees is a program that offers $25 coupons for trees from their recommended tree list, and there are trees of all sizes from which to choose. There are four participating nurseries in Frederick County and there is no limit to the number of coupons you can use. The county’s new program, Creek ReLeaf, will pay landowners with larger swaths of land to plant trees and establish conservation easements over those plantings.

There are plenty of ways to help increase tree canopy in Frederick, whether it’s a small tree in a postage-stamp yard or a riparian buffer next to a stream.

Author Spotlight

Jenny Willoughby

Jenny is currently the Sustainability Manager for the City of Frederick. She has worked in the natural resources field for more than 20 years. Most of those years were spent breaking down complex science topics into terms that citizens, school groups, church groups, homeowner associations, scout troops and others could easily understand. She is an ISA certified arborist and consider muddy boots and hands to be the sign of a good day at the office.